o1-mcp

An MCP server that exposes the o1.exchange DEX aggregator — live swap quotes and routing on Base — to any MCP client (Claude Desktop, Claude Code, …). Read-only and safe by default: no private keys, no signing, no broadcasting. It returns routing data and, optionally, unsigned calldata you sign in your own wallet.

Tools

The two gated tools register only when O1_ENABLE_BUILD_TX=true. They never sign or broadcast — you do, in your own wallet.

o1_get_quote takes tokenIn, tokenOut (an EVM address or "ETH"), and amountIn (base units / wei, as a string > 0). Optional: slippageBps (default 100, capped at 2000 unless O1_ALLOW_HIGH_SLIPPAGE=true), chainId, maxHops, splitEnabled, allowedDexes, feeBps, timeBudgetMs. It returns:

{
  "quoteId": "…", "expiresAt": 1782700000000,
  "expectedAmountOut": "…", "minAmountOut": "…",
  "feeBps": 5, "gasUnits": "210000",
  "venues": ["AERODROME_V2LIKE", "UNIV3"],
  "routesCount": 2,
  "note": "quote expires ~10s",
  "raw": { /* full /quote response */ }
}

Selling ETH? Set useNativeIn: true on the gated tools, or the calldata's value comes back 0. Quotes expire in ~10s and are never cached.

Related MCP server: Uniswap Trader MCP

Demo

Verified live in Claude Code — the read-only tools load and respond against production:

o1_health → ✅ /health returned { ok: true } · o1_list_supported_dexes → 21 DEX venues on Base (chain ID 8453). The gated o1_build_swap_transaction and o1_execute_swap tools appear once O1_ENABLE_BUILD_TX=true.

Tools for o1 — 3 tools
  1. o1_health                read-only, open-world
  2. o1_get_quote             read-only, open-world
  3. o1_list_supported_dexes  read-only

o1_list_supported_dexes → UNIV2, UNIV3, UNIV4, AERODROME_V2LIKE, AERODROME_CL, PANCAKE_V2, PANCAKE_V3, PANCAKE_INFINITY_CL, HYDREX, QUICKSWAP_V4, ALIEN_BASE_V3, CURVE, PROPSWAP, TESSERA, ELFOMOFI, LUNARBASE, FELTIR, DODO_V2, WOOFI, GYROSCOPE_ECLP, MAVERICK_V2.

Quick start

Requires Node 20+.

npm install
npm run build
cp .env.example .env   # set O1_API_KEY and O1_API_BASE_URL

Add it to your MCP client (stdio):

{
  "mcpServers": {
    "o1": {
      "command": "node",
      "args": ["/absolute/path/to/o1-mcp/dist/index.js"],
      "env": {
        "O1_API_BASE_URL": "https://quiet-bloodhound-531.convex.site",
        "O1_API_KEY": "your-key-here"
      }
    }
  }
}

Claude Code: claude mcp add o1 -- node /absolute/path/to/o1-mcp/dist/index.js.

Environment

Safety

• Read-only by default — swap-building tools are opt-in via O1_ENABLE_BUILD_TX.

• No private keys, ever — no tool accepts one, and output is always unsigned.

• Inputs validated before any network call — address format, amountIn > 0, slippage cap, chain allowlist.

• Secrets redacted from every log and error; logs go to stderr only (stdout carries only the MCP stream).

• Errors mapped — 400 invalid input · 401 auth · 429 rate-limited (with backoff) · 5xx upstream. Reads (/health, /quote) retry with backoff + jitter; writes (/submit, /execute) never do.

Development

npm run typecheck   # strict tsc
npm run lint        # eslint
npm test            # vitest (mocked fetch — no live network)
npm run dev         # run from source via tsx

License

MIT